Making Existing Homes Carbon Free

There are 28.7 million homes (1) within the UK with 23 million being heated by gas boilers.(2) New build homes are easy to decarbonise through renewable heating sources and high levels of insulation and air tightness, the real challenge lies in decarbonising the homes we already live in.

Around 80% of homes that will be occupied in 2050 (3) have already been built and will have gas boilers, lack sufficient insulation to easily be converted to renewable sources of heating and hot water, making them ill-equipped for a carbon free future.

While installing renewables like solar panels or heat pumps in individual homes can help, they remain costly and challenging to roll out at scale. Research by Professor Lucelia Rodrigues, Professor of Sustainable and Resilient Cities at the University of Nottingham has shown costs can be as high as £69,000 per home. (4) To retrofit every home would cost £1.58 trillion pounds, the tax payer cannot afford this amount and it will be difficult to convince every private owner to spend these large amounts.

In 2024, renewable sources accounted for 59% of the UK’s electricity generation(5), yet about 80% of homes still use gas boilers.(2) Electrifying heating and hot water through technologies like heat pumps and solar is one solution, but this shifts pressure to the electricity grid - currently reliant on fossil fuels. Without greening the production/grid you won’t achieve operational zero carbon.

Investment in the national grid to make production carbon free is required even if £1.58 trillion pounds is spent on individual homes. Therefore, we propose a shift in investment by the government to focus on making electricity production carbon free via nuclear or renewable sources before deep retro-fitting homes. The government should ensure the production and grid is state owned even if it is run by private companies to ensure maximum efficiency. The cost of electricity should be at cost to reduce household bills. A clean, decarbonised grid benefits all households, regardless of individual upgrades and reduces carbon emissions. It would require £550 billion to provide a net-zero power system according to Carbon-Free Europe, a fraction of the cost of retrofitting every home in the UK.(6)

Gradually, as the grid becomes carbon free, existing gas boiler homes can be converted to have electric boilers typically costing £3,500 per homes.(7) A total of £80.5 billion for the country which is a more realistic approach for individuals to afford and could be phased across a 10 year period without government grants as existing boilers break and require replacement.

Over time, homeowners could retrofit their homes to lower demand/cost of electricity to heat their homes but it allows people who simply cannot afford to spend large amounts to be carbon free.  

This approach deals with climate change quicker for a far less cost benefiting everyone. It uses existing technology being installed by the current workforce with existing skills and could remove gas boilers and fossil fuel electric generation within 10 years.

Sources:

1. Analysis from IBIS World

2. U Switch / Climate Change Committee

3. UK Green Building Council

4. Nottingham Carbon Neutral Housing: Cost vs Carbon Retrofit Roadmap research by University of Nottingham

5. National Energy System Operator

6. Carbon-Free Europe – Net-Zero Unveiled UK

7. Checkatrade – Boiler Costs 2025